Bacteria in the gut and chemical reactions caused by digestive acids create much of the intestinal gas people produce. The human digestive system generates from 500 to 2,000 ml of gas daily, vented as often as 40 times per day, according to Better Health Channel. The pulsating movements of vigorous exercise can trigger involuntary venting, but other parts of the exercise regimen can also contribute to this embarrassing problem.
Normal digestive processes produce gas. Pancreatic fluids neutralize excess stomach acid, producing carbon dioxide. Beneficial bacteria break down complex carbohydrates and digestible fiber, creating methane, hydrogen and oxygen gases. Complex carbohydrates -- an important fuel for athletes -- can create gas problems if the diet doesn't include the enzymes needed for digestion. Digestive supplements taken with problematic foods like beans or milk increase the digestive efficiency and reduce gas.
Most of the gases in flatulence contribute no odors, but bacteria in the colon add sulfur to the mix, accounting for part of the noxious smell. Any food that smells unpleasant in the kitchen blends that same aroma into the gassy byproducts of digestion. Foods like turnips, garlic and brussels sprouts may not increase the total amount of gas produced, but do make the problem more noticeable. Brown rice, however, provides complex carbohydrates and fiber without creating unpleasant gassy side effects. Rice contains the only starch that produces no gas, says the National Digestive Diseases Information Clearinghouse.
Most of the gas you vent by belching or through flatulence comes not from the digestive process, but from the air you swallow. Eating or drinking rapidly, common behavior among athletes, increases the amount of air gulped. Drinking from bottles, straws and drinking tubes also cause more air ingestion, and any air swallowed must either exit through the mouth or the anus. Chewing food thoroughly aids digestion and avoids excess aerophagia, or air swallowing, fighting flatulence in two ways.
Twenty to 50 percent of long-distance runners suffer from Runner's Trot, the common name for unusual bouts of diarrhea and flatulence, accompanied by severe cramps and nausea, notes the Time-to-Run website. Problems hit exercisers both during and after intense workouts. Dehydration could cause diarrhea, so staying hydrated helps avoid serious trouble. Many of the symptoms of Runner's Trot match those of irritable bowel syndrome, or IBS, and may be related to the extra psychological stress of competition, according to an article in "The Western Journal of Medicine." Intense exercise also shunts blood flow away from digestive organs, making the digestive system less able to deal with problems. Avoiding caffeine and dairy products, not eating for two hours prior to your workout and ensuring you'll have access to a bathroom cut the risk of embarrassment. If problems continue, consult your physician.
- Better Health Channel: Flatulence
- National Digestive Diseases Information Clearinghouse: Gas in the Digestive Tract
- "The Western Journal of Medicine"; Gastrointestinal Symptoms of Marathon Runners; Emmet B. Keeffe, et al.; October 1984
- Time-to-Run: Runner's Trots - The 'Plague' of the Exerciser
- CVS/Pharmacy Health Resources: Farewell to Flatulence; Laurie Udesky; 2009